It may be hard to imagine it now, but there was a time when the Black Eyed Peas were primarily known for the serious, socially conscious side of its music. Early albums like Bridging the Gap and Behind the Front gave the group a reputation for being one of the more literate and socially aware acts in hip-hop.

Even when the core trio — will.i.am, apl.de.ap and Taboo — added photogenic vocalist Fergie to its lineup and scored its breakthrough hit, they did it with "Where Is the Love," a song that addressed the atmosphere of mistrust, fear and aggression that was left in the wake of 9-11.

A preoccupation with lovely lady lumps changed all that.

The group's last two albums, Monkey Business and The E.N.D., have found the foursome riding a wave of light-hearted (some might say light-weight) pop concoctions ("My Humps," "Boom Boom Pow") to the top of the charts.

While some critics have accused the Black Eyed Peas of dumbing down the music in order to broaden the appeal, Taboo offers a different explanation. To him, the lighter side of the Peas simply reflects what has always been a key personality trait of the group.

"The thing about Black Eyed Peas is we're very humorous," says the vocalist and keyboard player. "All we do is laugh all day. When we're doing interviews, we laugh. We don't take anything too seriously. Life is too short to be serious. We like to have fun with it. That's why this album [The E.N.D.] is a club record. We like to go to clubs. We like to dance. We like to have a good time. We're best friends that get to travel the world and create a movement. That's what's special about Black Eyed Peas."

One part of that movement involves moving massive amounts of product. With worldwide sales at 26 million, the Black Eyed Peas are the best-selling hip-hop act in music today. The first two singles from The E.N.D. — "Boom Boom Pow" and "I Gotta Feeling" — set a record by topping Billboard magazine's top 40 singles chart for a combined 26 consecutive weeks, the longest stretch that any act had managed to keep a grip on the No. 1 single slot.

Sales of the album, which gives the band's music something of an electronic edge, currently stand at 9 million copies worldwide, an accomplishment that wasn't hurt by the group taking home freshly minted Grammy Awards for Best Pop Vocal Album and Best Performance by a Duo or Group.

Now the Peas are riding this wave of success into the live arena, beginning their first U.S. tour in three years. Taboo says he and his bandmates are stepping up their visual game to match their escalating popularity, courtesy of a custom-built stage complete with elevators, trap doors and video.

"For us, it's something we've never had before," he says. "There's a little bit of choreography in a couple of songs with the dancers we have. It's a little bit more of a spectacle."

As a black belt who wound up co-starring in a Street Fighter movie last year, Taboo enjoys having his own kinetic energy magnified ever further: "With four people on stage jumping around, it was great energy and we won people over for many years. But we felt the fans, the 'Peabodies,' deserved a better performance and a better presentation with this tour."